In order to properly size the water softener
unit you need, some known factors regarding the incoming water to be softened
are required. These calculations presume you have tested your incoming
water to know the following:

Hardness Rating: expressed in grains of hardness per gallon

The level of Iron: expressed in PPM (parts per million) or
M/L (milligrams per liter)

The level of Manganese: same expressions as per iron (PPM
or M/L)

The only other factor needed to size your water softener
is to determine the population served by the unit. Typically, this
is the number of permanent residents (adults and children) in the household.

Calculations:

1. Calculate DEMAND -- Start by multiplying the population
served times 80 (for general calculations, figure 80 gallons per day water
usage per person). Example: a 4-person household would calculate to 320
gallons per day demand.

4. Multiply DEMAND by the Calculated Equivalent Hardness
Value. This will give you the GRAINS PER DAY figure. Example: 320 gallons
times a Calculated Equivalent Hardness Value of 13 = 4,160 grains of hardness
per day.

5. It is most economical to size your water softener
so that it does not need to regenerate more often than once a week. So,
multiply the calculated grains of hardness per day by 7. As per example
above: 4,160 grains x 7 = 29,120 grains per week.

In the example above, the H2O-M2010 (30,000 grain) water
softener would be the properly sized unit. Capable of accommodating 29,120
grains of hardness removal per regeneration.

NOTE: If your water tests over 1 ppm for Iron, you should
consider iron removal pre-treatment technology. Contact ESD at 304-721-8380
or to discuss iron
removal.